Coal cleaning apparatus



April 27, 1937. K. PRINS v COAL CLEANING APPARATUS Fi led Feb. 6, 1953 2 Sheets-Sheet 1 April 27, 1937. K PRINS COAL CLEANING APPARATUS Filed Feb. 6. 1953 2 Sheets-Sheet 2 a w Q N m [WI Em EFT 27% air 32 '72 a Patented Apr. 27, 1937 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to coal cleaning apparatus for separating and removing slate, shale, stone, and other refusematter from coal, such refuse material being usually present in coal to a greater or less degree as it comes from the mine. o

Myimproved cleaning structure is of the type in which a medium having buoyant characteristics; such as sand or. small size coal, is used as a conveying body and separating medium for the coal to be cleaned, an important object of the invention being to produce such travel of the buoyant or flotation material that the slate, shale, stone and other refuse or non-combustible mal5 terial will quickly seek the lower level but the pure coal lumps will remain at the surface, the operation being such that air or other current or pulsations are unnecessary, thus materially reducing the cost of manufacture.

A further important object is to provide improved meansfor skimming off the clean coal from the top of the travelling mass and conducting it to a place of deposit or to a conveyor.

Another important object is to provide bafiiing and direction changing means in the path of the flotation material for cooperating with the skimming mechanism to efficiently skim the clean coal for withdrawal and diversion from the mass.

A further object is to provide means for vibrating the frame over which the mass travels so as to give forward and slightly upward impetus to the mass so that it will travel in fixed paths along the frame for the most efficient separation of the coal from the flotation material.

Still a further object is to provide improved means for separating the refuse matter collected in the flotation material and returning this material to the vibrated frame for recirculation thereoverl The various features of my invention are incorporated in the structure disclosed on the drawings, in which drawings Figure 1 is a side elevation, partly in vertical longitudinal section, of the structure;

Figure 2 is a plan View;

Figure 3 is an enlarged vertical section of part of the structure;

Figure 4 is a section on plane IVIV of Figure 3.

The structure shown comprises a frame designated as a whole A and comprising side walls 10 and H between which and secured at their ends thereto are transverse bottom wall sections I2. Cross shafts l3 below the frame A journal in 55 brackets l4 and links or blades l5 extend from the ends of these shafts which at their lower ends receive shafts l6 journalled in stationary supporting beams l'l. Pins l8 extending from brackets l9 depending from the bottom of the frame journal the connecting rods 2 which at their outer ends have eccentric connection with a shaft 2|, which shaft is rotated as by means of a belt 22 engaging the pulley or wheel 23 on the shaft and the driving pinion 24 of a suitable motor 25.

The frame A is slightly inclined from the horizontal, its discharge end at the right being lower than the receiving end at the left, and the links or blades I5 are slightly inclined toward the left from the vertical so that when the motor is running the eccentric connection will give the frame a combined longitudinal and slightly vertical reciprocation.

Each bottom wall section I2 of the frame A has the front part X which inclines with the frame, and a rear part Y which does not have so great an inclination and may be substantially horizontal as shown. Extending between and connecting the end of each part Y with the front end of the part X of the next bottom section I2 is a vertical wall 26 which extends a distance upwardly beyond the end of the part Y and is deflected rearwardly to form a sill 26, the projecting part of the Wall and the sill forming a baffie. The bottom sections and these end walls define compartments or pans through which the flotation material travels when the frame A is vibrated. The flotation material 21, which may be sand, but is preferably small size coal, is fed from a hopper 28 through a spout 29 onto a plate or apron 30 which has substantially the same inclination as the frame A and terminates below the top of the vertical wall 26 for the first compartment or pan C--l The flow of the flotation material from the hopper may be controlled by a suitable valve or gate 3i.

When the frame A is vibrated the vertical walls 26 of the compartments will serve to impel the flotation material gradually toward the outlet end of the frame, the sections of the wall 26 above the compartment bottoms obstructing and baffling the flow of the material. Other bafile means in the form of short vertical walls or steps 32 are provided in each compartment-adjacent to the vertical wall 26 thereof.

At the end of the last compartment or pan C3 a raised sieve or grating 33 is interposed in the path of the travelling flotation material, the material itself falling through the grate to be delivered by a spout 34 to a conveyor belt 35,

the collected refuse matter flowing across the grating into a spout 36 to be collected in a pile or to be received by conveyor mechanism (not shown) for conveyance to any point desired.

The conveyor belt 35 travels around end pulleys 31 and 38, the top leg of the belt being supported by pulley sets 39 and the bottom leg of the belt traveling over rolls or pulleys 40. A plate or beam 4| forms a support for the pulley structures 31, 39 and 4|], while the end pulley 38 is supported by the inlet frame 42 extending from the vertical conveyor frame 43, the material conveyed by the belt being discharged into the inlet frame from where it flows into the conveyor frame 43 to be received by the buckets 44 on the elevator belt 45 extending around the pulleys 46 and 41 within the frame 43. A belt 48 connects a pulley 49 on the shaft 40 with the pulley 56 on a counter shaft 5I which shaft is connected by reducing gearing 52 with the shaft which supports the belt pulley 38. A pulley 53 on this shaft isconnected by belt 54 with the pulley 55 on shaft 56 which shaft has connection by means of a belt 51 with the pulley 58 on the shaft 59 which supports the upper pulley 41 for the conveyor belt 45. A duct 66 receives the hoisted material from the buckets 44 for return of the material t0 the hopper 28.

The coal 6| to be cleaned is delivered from ahopper 62 to an apron or plate 63 extending between the side walls of the frame A a distance above the apron 30 and terminating a distance in advance of the wall 26 of the first compartment CI to leave a gap 64.

Over each of the pan or compartment sections CI, C2, C--3 is a skimmer structure, the skimmer structure being designated S, S-I S2 and S3. Each skimmer structure comprises a plate 65 of sheet metal whose front part is deflected downwardly and rearwardly to form a front baffle wall 66 and the inclined bafile wall 61 underneath the plate. The plate extends transversely between the side walls In and I I of the frame A and at its sides has flanges 66 extending downwardly against the inner sides of the frame walls Ill and I I and at their ends these flanges are provided with horizontal and vertical slots 69 and I6 through whose intersections bolts II pass, the bolts extending through the frame side walls In and II, these bolts and slots serving as a means for adjusting the skimmer plate 65. On each skimmer plate is mounted a V or plow shaped frame I2 of sheet metal, the point of the frame being a distance rearwardly of the front wall 66 of the skimmer plate. Each skimmer structure is located a distance above the rear part Y of the bottom I2 of the corresponding compartment or pan section, the rear edge of each skimmer plate 65 terminating a distance in front of and above the sill 21 of the next compartment or pan section to leave a gap I3 through which the flotation material 2'! passes. Between each gap I3 and the front Wall 66 of the next skimmer structure is an opening 14 through which any coal carried by the flotation material may pass to be received on the skimmer structure and between the gap 64 at the end of the flotation material and coal feeding aprons 30 and 63 respectively and the front wall 66 of the first skimmer structure is the opening or passageway I4. Adjacent to the skimmer structures the side walls Ill and I I of the frame A have, a distance below the tops thereof, the laterally extendinghorizontal walls I5 and I5 whose outer ends are deflected vertically upwardly to form walls 16 and 16, these walls defining the passageways or troughs TI and 11 for clean coal separated from the mass by the skimmer structures. At their front end the walls I6, 13' are deflected to be parallel with the plow or diverter structure I2 on the first skimmer structure F-I. At their rear ends the walls 16, I6 and the walls I6 and II deflect toward each other to form the diagonal section of the troughs H, H for discharging coal into the discharge end I8 from which the coal flows onto a suitable conveyor structure 79 to be conveyed to the desired point. Adjacent to the troughs or diverter structures of the skimmer structure the walls I0 and II of the frame A have the openings 80 and 89 respectively for the passage into the troughs or runways I! and T! of the coal diverted by the plow structure.

Describing now the operation, the compartment or pan sections are full of the flotation material such as sand or small size coal which is fed from the hopper 21 in regulated quantity so as to maintain a proper level in the pan sections. The coal is fed at a proper rate from the hopper 62.

pan structure to the other, the flow of the flotation material and coal to the first pan structure being gravitational and also by the reciprocation effect of the frame A, this feed flow being along the aprons 30 and 63 respectively.

As the material flowing along the apron 30 encounters the baffle wall 26 of the first pan section CI, the lower part of the mass is retarded and the upper part rises to flow over the sill 26. This upward surge of the flotation material meets coal coming down the apron 63 and tends to raise this coal and prevent it from sinking into the flotation mass. Refuse particles mixed with the coal, such as stone, shale, slate or the like being heavier than the coal, they will tend to sink in the flotation mass. After the mass passes the sill 26 it will pour rapidly into the pan section C--I as immediately behind the baffle plate 26 and above the step 32 the separating medium shows a distinct difference in density, allowing the heavier refuse material to sink rapidly and become embedded in the medium under the clean coal which floats along over the medium. The entire mass now moves toward the first skimmer structure S-I where it will encounter the vertical wall or edge 66 of the skimmer structure and will be again baflled, such bafiling compacting the flotation or separating material in front of the wall so that the clean coal will tend to remain on top and will pass onto the skimmer plate 65 of the first skimmer structure, while any refuse matter which may encounter the wall 66 will be dragged down below the skimmer plate by the flotation material which tends to flow along past the material obstructed by the wall 66. The clean coal received on the skimmer structure flows along the sides of the plow frame I2 and flows into and along the troughs TI and TI to eventually reach the conveyor 19.

The flotation material with the collected refuse matter therein continues along the pan structure CI, and by encountering the less inclined or F horizontal part Y of the pan floor and the baffle wall 26 of the second pan structure C--2, it is retarded or baffled and forced upwardly more or less against thebottom of the skimmer plate 65 of the skimmer section S-I until the gap I3 When the motor 25 is started the frame A is reciprocated with a combined longitudinal and above the sill of the second pan structure is reached when the material will flow over this sill and into the second pan structure 0-2. Due to the large amount of coal received at the first pan section, only the upper layer of coal may be skimmed off here, and some of the coal may sink sufficiently in the pan section to be carried along with the flotation material and refuse matter toward the second pan section. This coal will, however, tend to remain at the surface of the flotation material passing through the first pan section and will be lifted upwardly as the flotation material flows over the sill of the second pan section while the refuse matter lower down and closer to the sill will drop quickly after passing the sill, the clean coal then travelling along the top of the flotation material in the second pan section until the front wall 66 of the second skimmer structure S2 is reached, whereupon the coal at the top of the flotation material will pass onto the skimmer plate of the second structure and the flotation material and refuse matter will continue through the second pan section on its way to the third pan section where the same cycle of separation takes place, there being enough pan sections and skimmer structures so that, when the last skimmer structure is passed, practically all of the clean coal will have been separated from the refuse material. The skimmer structures being adjustable, careful setting there of can readily be made for the proper and efhcient skimming off of the clean coal. The coal skimmed off by the second and third skimmer structures flows through. the openings and 80 into the side troughs 11 and H to flow therethrough on its way to the conveyor 79.

The reciprocation of the frame A and the rate of feed of flotation material are such that this material will reach and maintain the level providing the best skimming action. After travel of the flotation material with the accumulated refuse matter from the coal, it flows over the grating the fine material flowing through the grating and through the spout 36. The material flowing through the grating is delivered by the chute 34 to the travelling belt which conveys it back to the elevator for recharge into the hopper 21 and for redelivery to' the frame A and recirculation therethrough.

Some of the flotation material or separating medium may be carried over the skimmer plates. Where this medium is sand this would not be desirable; but where the medium is in the form of small size coal it would not matter so much as such coal is combustible. To prevent such escape of material with the clean coal, the lower edges of the plow or diverter structures 12 may be provided with diverter openings through which any separating material received on the skimmer plates may flow to the inside of the plow structure to flow along the skimmer plate and drop 01? the end thereof back into the corresponding pan section. Any small pieces of coal that may be broken off the larger coal lumps will also find their way through the opening 85 and down into the pan section.

Although my improved apparatus will operate successfully with sand or fine coal as the flotation or separating medium, I find that larger size coal pieces will give much more eflicient results. Where the coal to be cleaned is of a larger or lump size, I find that coal pieces, even of the size of pea coal, will give efficient results when used as the flotation and separating medium. This is probably explained by the fact that, whereas the resistance between particles of sand or fine coal is comparatively large, the resistance between the pieces of larger size coal is comparatively small and the fluidity characteristics of a mass of such larger coal pieces is much greater than that of sand or fine coal. The heavier refuse pieces such as stone, slate, slag, etc. can readily find their way down into the mass, while the coal lumps will tend to remain on and float along the top of the separation mass or medium. Where sand or fine coal is used as a flotation and separating medium, its operation would be materially influenced and disturbed by dampness or moisture, whereas if such medium is of larger pieces of coal, ordinary dampness or moisture would have no material effect.

My improved structure is very simple and can be economically manufactured and is very efficient in operation. I do not desire to be limited to the exact structure and operation shown and described, as changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.

I claim as my invention:

1. In apparatus of the class described, the combination of an inclined imperforate chute frame having baffle walls rising from its bottom to form pan sections, said sections containing dry flotation material, means for imparting combined longitudinal and vertical reciprocation to said frame 1 whereby said partitions will tend to impel the flotation material downwardly along said chute frame, means for feeding flotation material to the first pan section and means for feeding coal to be cleaned to the first pan section above the flotation materials therein, a horizontally disposed skimmer structure above each pan section separate thereof and a distance rearwardly of the en trance end thereof and presenting a skimming edge to thetravelling mass and for skimming and receiving clean coal from the top of the travelling mass, and means for adjusting said skimmer structures.

2. In apparatus of the class described, the combination of a chute frame having baffle walls rising from its bottom to form a series of pan sections for containing dry flotation material, means for imparting combined longitudinal and vertical reciprocation to said frame to cause said baffle walls to impel said material forwardly through said chute frame, means for feeding flotation material to the first pan section and means for feeding coal to be cleaned to the first pan section above the material therein, a horizontally disposed skimmer plate over each pan section whose front skimming edge is located a distance to the rear of the baffle wall of the respective pan section and whose end terminates a distance in front of the baiile wall of the next pan section, said skimmer plates serving to skim clean coal from the top of the flotation material and the heavier refuse particles sinking in the material to travel through the pan sections below the skimmer plates, and means for adjusting the skimmer plates.

3. In apparatus of the class described, the combination of a chute frame having a row of transversely extending and upwardly projecting baflle walls at its bottom, each wall terminating at its top in a laterally extending sill, said walls forming a series of pan sections for containing dry flotation material, means imparting a combined longitudinal and vertical reciprocation to the chute structure to cause said baffle walls to impel the material forwardly through said pan sections, means for feeding flotation material to the first section and means for feeding coal to be cleaned to the first pan section above the material therein,

a horizontally disposed skimmer plate above each pan structure for skimming the clean coal from 5 the top of the material, and means for conveying away the skimmed off coal.

4. In apparatus of the class described, the combination of a chute frame having a row of upstanding baffie walls defining pan sections which communicate serially and contain dry flotation material, means for causing said material to flow gradually from one pan section to the other, means for feeding material to the first pan section, means for feeding coal to be cleaned to the first pan section over the material therein, a substantially horizontally disposed skimmer plate a distance above each pan section presenting at its front end a shallow upright skimmer wall to the advancing mass for baffling the flotation material and skimming from the top thereof the cleaned coal, and means for collecting the cleaned coal from the skimmer plates.

5. In apparatus of the class described, the combination of a chute frame having bafiie walls extending across and rising from its bottom and terminating at their upper ends in laterally extending sills, said walls defining a series of pan sections for containing dry flotation material, means for causing said material to flow over said sills from one pan structure to the other, means for feeding material to the first pan section and means for feeding coal to be cleaned to the first pan section above the material therein, a horizontally disposed skimmer plate over each pan section presenting a shallow upright skimming wall to the oncoming mass and terminating above the baffle wall of the next pan section, said skimming wall being at a level to baflie the flotation material and skim from the top thereof the clean coal after passage of the material over a sill, conveyor troughs alongside said chute frame and diverter structures on said skimmer plates for diverting the skimmed coal to said trough.

6. In apparatus of the class described, the combination of a downwardly inclined chute frame having cross walls rising from its bottom to divide said frame into pan sections and having laterally extending sills at their upper ends, flotation material in said pans in the form of small size coal, means for imparting combined longitudinal and vertical reciprocation to said frame where said walls will urge said material to travel downwardly through said pans, means for feeding flotation material to the first pan section, means for feeding coal to be cleaned to said first pan section onto the flotation material therein, a horizontally disposed skimmer plate above the bottom of each pan extending across the chute structure and having a front baflie and skimming wall and ter mating a distance in advance of the next pan section, said skimming wall skimming clean coal from the top of the flotation material and the heavier refuse particles sinking in the material and travelling along therewith below the skimmer plate to be received in the next pan section, conveyor troughs running alongside said chute structure skimmer plates, and V-shaped deflector structures on said skimmer plates for directing the skimmed coal to said troughs.

'7. In apparatus of the class described, the combination of a downwardly inclined chute frame having cross walls rising from its bottom to form a series of pan sections and terminating in laterally extending sills, a step in each pan section below the respective sill, flotation material in said pan sections in the form of small size coal, means for imparting combined longitudinal and vertical reciprocation to said frame whereby said material will be agitated and said walls and steps will impel said material to flow gradually through said pan sections, means for feeding flotation material to the first pan section, means for feeding coal to be cleaned to the first pan section onto the flotation material therein, a horizontally disposed skimmer plate above the bottom of each pan section having a front skimming edge and terminating a distance in advance of the next pan section, said skimming edge skimming clean coal from the top of the flotation material and the heavier refuse matter sinking in said material to be carried through the pan section below the skimmer plate and into the next pan section, said skimmer plates being adjustable, and means for conveying away from said skimmer sections the cleaned coal received thereby.

8. In apparatus of the class described, the combination of a series of steps forming an inclined chute for dry flotation material, means for 1mparting combined longitudinal and vertical reciprocation to said chute for impelling the flotation m terial forwardly from one step to the next lower step, baflle sills extending upwardly at the junctures of said steps over which the flotation material must flow during its passage through said chute, a skimmer structure above each step having a front skimming edge disposed a distance rearwardly of the front bafile sill for said step and having its rear end terminating a distance above the sill at the end of said step to form a restricted gap, means for feeding onto the flotation material at the forepart of said chute the coal mass to be cleaned, the flotation material in flowing over said sills and through said gaps tending to urge the coal particles to flow along the top of the material and onto the skimmer structures for skimming thereof from the material and directing the heavier refuse particles for sinking into the material after passage over the sills.

9. In apparatus of the class described, a series of steps forming a path for dry flotation material, means for imparting combined longitudinal and vertical reciprocation tosaid step structure tending to impel the flotation material forwardly thereon progressively from one step to the next lower step, means for feeding onto the flotation material at the beginning of said path the coal mass to be cleaned, a skimmer structure disposed above each step and the flotation material passing therethrough, and a bafile sill extending upwardly from the front end of each step and in advance of the skimmer structure over the next step over which sill the flotation material must flow, the flotation material when flowing over a sill urging the coal particles upwardly and toward the respective skimmer structure and permitting the refuse heavier particles to move downwardly with the flotation material down to the next step.

KLAAS PRINS. 

